The present invention relates to an apparatus for, and a method of, laying a pipe line composed of individual pipe sections arranged end-to-end.
In the construction of a pipe line it is well known to excavate an open-trench and to lower the individual prefabricated pipe sections into the trench which is subsequently refilled. Planks or frameworks can be used to support the walls of the trench while the pipe sections are introduced and connected together. This known method is problematic especially where the ground is water-logged and/or where relatively large diameter pipe sections are used.
One form of apparatus which is useful in coping with these problems uses a box-like receptacle into which the pipe sections are introduced.
With certain types of pipe line it is known to provide line access tubes or shafts which communicate with the line at intervals. For this purpose some of the pipe sections, which are usually prefabricated concrete structures, have integral therewith an upstanding access tube which can provide connection to the pipe line at a certain position along its length -- typically 50-70 meters apart. Where these special pipe sections are used the upstanding tubes thereof cause difficulties especially with regard to the sealing of the receptacle in water-logged ground.
A general object of this invention is to provide an improved method and apparatus designed to accommodate these special pipe sections.